Sony has been in the news of late for its radical new tech that crams 185TB of data onto a single analog-style cassette tape. That's a very different story -- I'm referring to old-school, all-analog music cassettes that indie labels and DIY artists are cranking out now.
When I chatted with a clerk at Other Music in Greenwich Village, he told me genres are mostly limited to new garage rock, noise, and experimental electronic fringe stuff, but the store has sold cassettes for quite a few years. The difference is there's a lot more cassettes coming out over the past year or so. He admitted collectibility among college-age customers might be part of cassette's appeal, but older folks are also looking for tapes.
Analog cassette players are hands-on machines; most don't have remote controls, just like the other analog "player," aka turntables. That's what I like about analog formats: you have to get physically involved to play them. Cassettes were the original "lo-fi" format, but that never hindered their popularity in the '70s, '80s and '90s.
Another big draw for cassettes is price -- they were always cheap, and they now sell for half of what CDs go for, and a lot less than new LPs.